【作者】 王凯；

【导师】 贾星兰；

【作者基本信息】 中国石油大学 ， 安全技术及工程， 2010， 硕士

【摘要】 随着油田勘探程度的日趋提高,低渗透油藏探明储量的比例逐步提高,欠平衡钻井技术也随之不断的发展。在欠平衡钻井过程中,钻井液循环到地面过程中的脱气处理对欠平衡钻井具有及其重要的作用。因为在欠平衡钻井过程中,钻井液中会充入各种气体,以降低钻井液的密度,若是不能有效的进行地面脱气处理,一方面将会带来很大的安全隐患,影响钻井工艺参数计算和测量数据的准确性,使井下情况判断更加复杂;另一方面将会影响钻井液循环和泥浆泵上水效率,在泥浆泵的上水阀、出水阀、活塞处产生水击现象,降低易损件寿命。此外还可能引起爆炸或恶性中毒等事件的发生。目前,国内外对欠平衡钻井液的地面脱气主要采用重力式气液分离器,重力式气液分离器存在着处理量小、分离效率低、操作复杂、不易于拆卸和维护等缺点,因此本文把气液旋流分离技术运用到高含气欠平衡钻井液的脱气处理中去。对欠平衡钻井液无害化处理的关键技术就是脱气处理,即本论文的中心内容:高含气欠平衡钻井液气液旋流分离器的优化及其技术研究。本论文主要采用计算流体力学(CFD)数值模拟方法研究了钻井液气液旋流分离器的内部流场,模拟出了旋流分离器内部气液两相流的压力分布,通过CFD软件模拟得出了气液两相流在分离器内部的轴向速度和切向速度的变化规律,得到了钻井液气液旋流器内部流场的特征;采用正交试验法和CFD软件模拟相结合的方法得出了影响钻井液气液旋流分离器分离效率的一些因素与旋流分离器分离效率的关系,这些因素包括:入口速度、长径比、液体的含气量、入口位置、钻井液的粘度、分离器的直径、气泡直径等,并把得出的结果与现实试验相对比,验证了CFD软件模拟的正确性,为钻井液气液旋流器分离器的工艺设计提供了理论参考依据。更多还原

【Abstract】 The proportion of low permeability oil reservoir is gradually increased with the development of oil exploration technology, which leads to constantly developing of the under-balanced drilling technology. Removing the gas from drilling mud during the mud circulation to the ground is very important in the under-balanced drilling process. A variety of gases will be swapped into drilling mud for reducing the density of drilling mud in the process of under-balanced drilling. If the gas can not be effectively removed in the ground degassing, it will be bright a great security risk, and affected the drilling process parameters and measurement accuracy of the data, made the situation underground to determine more complex; on the other hand, it will affect the efficiency of drilling fluid circulation and mud pump, and lead to the wearing of parts. It may also cause an explosion or malignant poisoning incidents. At present, degassing under-balanced drilling mud on the ground is mainly using gravity-type gas-liquid separator at home and abroad. Gravity-type gas-liquid separator has some defects, which handling of small amount, low separation efficiency, operation complex, not easy to demolition and maintain. Therefore, using of gas-liquid cyclone separation technology to separation of the gas from under-balanced drilling mud is this paper’s main task.The key component of harmless proceeding is the separation of the gas from under-balanced drilling mud, and this is also the main contents of this article: optimization of drilling mud gas-liquid cylindrical cyclone separator. The flow field in drilling mud gas-liquid cylindrical cyclone separator was studied using the computational fluent dynamics (CFD) method. The stress distribution, axial velocity and tangential velocity were simulated, and the flow field feature of the drilling mud gas-liquid cylindrical cyclone separator was also obtained. The relationships between some factors, which affect the separation efficiency of drilling mud gas-liquid cylindrical cyclone separator, and the separation efficiency of this cyclone separator were obtained. These factors include: the entrance speed, aspect ratio, the liquid containing gas, import position, drilling fluid viscosity, separator diameter, bubble diameter, etc., and made the results compared to the reality test to verify the correctness of simulation using the CFD software. This result provides guide lines for drilling mud gas-liquid cylindrical cyclone separator technical designing.更多还原